EP-B 105 341 (General Electric Company; published on Jan. 7, 1987) discloses organopolysiloxanes which contain, per molecule, at least one Si-bonded vinyloxy functional group of the formula EQU H.sub.2 C.dbd.CH--O--G--
where G is an alkylene radical or an alkylene radical which is interrupted by at least one divalent heteroradical such as --O--, a divalent phenylene radical or substituted divalent phenylene radical, or a combination of such radicals. These organopolysiloxanes are obtained by preparation of a compound containing one allyl and one vinyloxy group and addition of this compound onto the SiH groups of the polyorganosiloxanes, with the hydrosilylation occurring only on the allyl group. EP-B 105 341 also describes compositions which can be crosslinked by means of light and comprise the abovementioned organopolysiloxanes, and also onium salts which catalyze the cationic polymerization of these organopolysiloxanes.
Chemical Abstracts 107,176221q discloses the production of plastic lenses using a silane containing a vinyloxypropyl group and at least one trimethylsiloxy group, which silane is obtained by hydrosilylation of allyl vinyl ether with a trimethylsiloxy-containing silane, with the addition occurring on the allyl group.
US-A 5,057,549 (Wacker-Chemie GmbH; issued on Oct. 15, 1991) and US-A 5,231,157 (Wacker-Chemie GmbH; issued on Jul. 27, 1993) describe propenyloxy-containing organopolysiloxanes or propenyloxy-containing siloxane copolymers which are prepared in a two-stage process by addition of compounds containing two or more allyloxy groups onto SiH groups of organopolysiloxanes and subsequent conversion of the allyloxy groups into the propenyloxy groups by rearrangement of the double bond.
US-A 5,145,915 (Goldschmidt AG; issued on Sep. 8, 1992) discloses organopolysiloxanes containing any number of substituted vinyl ether groups which are prepared by hydrosilylation, i.e. by reaction of an organopolysiloxane containing SiH groups with a polyoxyalkylene ether, for example of the formula ##STR3## with the addition occurring on the allyl group.
DE-A 42 15 076 (Wacker-Chemie GmbH; published on November 11, 1993) describes vinyloxy-containing siloxane copolymers which are prepared by reaction of organic compounds containing a plurality of vinyloxy groups with organopolysiloxanes containing Si-bonded hydrogen atoms in the presence of hydrosilylation catalysts. Since the vinyloxy groups are all equally reactive, the hydrosilylation reaction does not occur selectively and the vinyloxy-containing organic compound has to be used in large excesses in order to obtain the desired vinyl ether siloxanes.